A previous study showed that BRCA1 interacts with EZH2 to inhibit its repression and the H3K27me3 on genes targeted by the PRC2 repressive complex in mouse embryonic stem and human breast cancer cells.22 We also showed recently that BRCA1 inhibits promoter methylation and chromatin silencing of FOXA1 through binding to EZH2.23 These findings raised the possibility that BRCA1 promotes FOXO3 expression through inhibiting EZH2 activity and histone lysine 27 trimethylation. This evidence concerns the gene EZH2 and breast cancer.